/Engine/Source/Runtime/MeshUtilitiesCommon/Public/Allocator2D.h
void MergeRun ( [FRun](API\Runtime\MeshUtilitiesCommon\FAllocator2D\FRun) & Run, const [FRun](API\Runtime\MeshUtilitiesCommon\FAllocator2D\FRun) & OtherRun, uint32 RectOffset, uint32 RectLength, uint32 PrimaryResolution, uint32 PerpendicularResolution )